Systemic therapies for preventing or treating aromatase inhibitor-induced musculoskeletal symptoms in early breast cancer.

BACKGROUND: Adjuvant aromatase inhibitors (AI) improve survival compared to tamoxifen in postmenopausal women with hormone receptor-positive stage I to III breast cancer. In approximately half of these women, AI are associated with aromatase inhibitor-induced musculoskeletal symptoms (AIMSS), often described as symmetrical pain and soreness in the joints, musculoskeletal pain and joint stiffness. AIMSS may have significant and prolonged impact on women's quality of life. AIMSS reduces adherence to AI therapy in up to a half of women, potentially compromising breast cancer outcomes. Differing systemic therapies have been investigated for the prevention and treatment of AIMSS, but the effectiveness of these therapies remains unclear. OBJECTIVES: To assess the effects of systemic therapies on the prevention or management of AIMSS in women with stage I to III hormone receptor-positive breast cancer. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, WHO International Clinical Trials Registry Platform (ICTRP) and Clinicaltrials.gov registries to September 2020 and the Cochrane Breast Cancer Group (CBCG) Specialised Register to March 2021.  SELECTION CRITERIA: We included all randomised controlled trials that compared systemic therapies to a comparator arm. Systemic therapy interventions included all pharmacological therapies, dietary supplements, and complementary and alternative medicines (CAM). All comparator arms were allowed including placebo or standard of care (or both) with analgesia alone. Published and non-peer-reviewed studies were eligible. DATA COLLECTION AND ANALYSIS: Two review authors independently screened studies, extracted data, and assessed risk of bias and certainty of the evidence using the GRADE approach. Outcomes assessed were pain, stiffness, grip strength, safety data, discontinuation of AI, health-related quality of life (HRQoL), breast cancer-specific quality of life (BCS-QoL), incidence of AIMSS, breast cancer-specific survival (BCSS) and overall survival (OS). For continuous outcomes, we used vote-counting by reporting how many studies reported a clinically significant benefit within the confidence intervals (CI) of the mean difference (MD) between treatment arms, as determined by the minimal clinically importance difference (MCID) for that outcome scale. For dichotomous outcomes, we reported outcomes as a risk ratio (RR) with 95% CI. MAIN RESULTS: We included 17 studies with 2034 randomised participants. Four studies assessed systemic therapies for the prevention of AIMSS and 13 studies investigated treatment of AIMSS. Due to the variation in systemic therapy studies, including pharmacological, and CAM, or unavailable data, meta-analysis was limited, and only two trials were combined for meta-analysis. The certainty of evidence for all outcomes was either low or very low certainty. Prevention studies The evidence is very uncertain about the effect of systemic therapies on pain (from baseline to the end of the intervention; 2 studies, 183 women). The two studies, investigating vitamin D and omega-3 fatty acids, showed a treatment effect with 95% CIs that did not include an MCID for pain. Systemic therapies may have little to no effect on grip strength (RR 1.08, 95% CI 0.37 to 3.17; 1 study, 137 women) or on women continuing to take their AI (RR 0.16, 95% 0.01 to 2.99; 1 study, 147 women). The evidence suggests little to no effect on HRQoL and BCS-QoL from baseline to the end of intervention (the same single study; 44 women, both quality of life outcomes showed a treatment effect with 95% CIs that did include an MCID). The evidence is very uncertain for outcomes assessing incidence of AIMSS (RR 0.82, 95% CI 0.63 to 1.06; 2 studies, 240 women) and the safety of systemic therapies (4 studies, 344 women; very low-certainty evidence). One study had a US Food and Drug Administration alert issued for the intervention (cyclo-oxygenase-2 inhibitor) during the study, but there were no serious adverse events in this or any study. There were no data on stiffness, BCSS or OS. Treatment studies The evidence is very uncertain about the effect of systemic therapies on pain from baseline to the end of intervention in the treatment of AIMSS (10 studies, 1099 women). Four studies showed an MCID in pain scores which fell within the 95% CI of the measured effect (vitamin D, bionic tiger bone, Yi Shen Jian Gu granules, calcitonin). Six studies showed a treatment effect with 95% CI that did not include an MCID (vitamin D, testosterone, omega-3 fatty acids, duloxetine, emu oil, cat's claw).  The evidence was very uncertain for the outcomes of change in stiffness (4 studies, 295 women), HRQoL (3 studies, 208 women) and BCS-QoL (2 studies, 147 women) from baseline to the end of intervention. The evidence suggests systemic therapies may have little to no effect on grip strength (1 study, 107 women). The evidence is very uncertain about the safety of systemic therapies (10 studies, 1250 women). There were no grade four/five adverse events reported in any of the studies. The study of duloxetine reported more all-grade adverse events in this treatment group than comparator group. There were no data on the incidence of AIMSS, the number of women continuing to take AI, BCCS or OS from the treatment studies. AUTHORS' CONCLUSIONS: AIMSS are chronic and complex symptoms with a significant impact on women with early breast cancer taking AI. To date, evidence for safe and effective systemic therapies for prevention or treatment of AIMSS has been minimal. Although this review identified 17 studies with 2034 randomised participants, the review was challenging due to the heterogeneous systemic therapy interventions and study methodologies, and the unavailability of certain trial data. Meta-analysis was thus limited and findings of the review were inconclusive. Further research is recommended into systemic therapy for AIMSS, including high-quality adequately powered RCT, comprehensive descriptions of the intervention/placebo, and robust definitions of the condition and the outcomes being studied.

Exercise therapies for preventing or treating aromatase inhibitor-induced musculoskeletal symptoms in early breast cancer.

BACKGROUND: Survival for stage I to III, hormone receptor-positive, breast cancer has substantially improved over time due to advances in screening, surgery and adjuvant therapy. However many adjuvant therapies have significant treatment-related toxicities, which worsen quality of life for breast cancer survivors. Postmenopausal women with hormone receptor-positive breast cancer are now prescribed aromatase inhibitors (AI) as standard, with longer durations of therapy, up to 10 years, being considered for certain women. AI treatment is associated with a high incidence of AI-induced musculoskeletal symptoms (AIMSS), often described as symmetrical pain and soreness in the joints, musculoskeletal pain and joint stiffness. AIMSS reduces compliance with AI therapy in up to one half of women undergoing adjuvant AI therapy, potentially compromising breast cancer outcomes. Exercise has been investigated for the prevention and treatment of AIMSS but the effect of this intervention remains unclear. OBJECTIVES: To assess the effects of exercise therapies on the prevention or management of aromatase inhibitor-induced musculoskeletal symptoms (AIMSS) in women with stage I to III hormone receptor-positive breast cancer. SEARCH METHODS: We searched Cochrane Breast Cancer's Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases up to 13 December 2018. We also searched two conference proceedings portals and two clinical trials registries for ongoing studies or unpublished trials, or both, in August 2019. We also reviewed reference lists of the included studies. SELECTION CRITERIA: We included randomised controlled trials that compared exercise versus a comparator arm. We did not impose any restriction on the comparator arm, which could include an alternative type of exercise, no exercise or a waiting list control. Both published and non-peer-reviewed studies were eligible. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data, assessed risk of bias and certainty of the evidence using the GRADE approach. The outcomes investigated were pain, joint stiffness, grip strength, health-related quality of life, cancer-specific quality of life, adherence to AI therapy, adverse events, incidence of AIMSS, breast cancer-specific survival and overall survival. For continuous outcomes that were assessed with the same instrument, we used the mean difference (MD); for those outcomes that used different instruments, we used the standardised mean difference (SMD) for the analysis. For dichotomous outcomes, we reported outcomes as an odds ratio (OR). MAIN RESULTS: We included seven studies with 400 randomised participants; one study assessed exercise for preventing AIMSS and six studies assessed treating AIMSS. For preventing AIMSS, the single study reported no difference in pain scores, grip strength or compliance to taking AI medication between groups. Data values were not provided in the study and no other outcomes were reported. For managing AIMSS, we found that the evidence for the effect of exercise therapies on overall change in worst pain scores was very uncertain (SMD -0.23, 95% confidence interval (CI) -0.78 to 0.32; 4 studies, 284 women; very low-certainty evidence). The evidence suggested that exercise therapies result in little to no difference in overall change in stiffness scores (Western Ontario McMasters Universities Osteoarthritis Index (WOMAC) stiffness score MD -0.76, 95% CI -1.67 to 0.15 and Visual Analogues Scale (VAS) stiffness score MD -0.42, 95% CI -2.10 to 1.26; 1 study, 53 women; low-certainty evidence). The evidence was very uncertain for the outcomes of overall change in grip strength (MD 0.30, 95% CI -0.55 to 1.15; 1 study, 83 women; very low-certainty evidence); overall change in health-related quality of life (subscales of SF-36 tool ranged from least benefit of MD 1.88, 95% CI -2.69 to 6.45 to most benefit of MD 9.70, 95% CI 1.67 to 17.73; 2 studies, 123 women, very low-certainty evidence); overall change in cancer-specific quality of life (MD 4.58, 95% CI -0.61 to 9.78; 2 studies, 136 women; very low-certainty evidence); and adherence to aromatase inhibitors (OR 2.43, 95% CI 0.41 to 14.63; 2 studies, 224 women; very low-certainty evidence). There were no adverse events identified across four studies in either arm (0 events reported; 4 studies; 331 participants; low-certainty evidence). There were no data reported on incidence of AIMSS, breast cancer-specific survival or overall survival. AUTHORS' CONCLUSIONS: Given the wide-ranging benefits of exercise for people affected by cancer, it was surprising that this review provided no clear evidence of benefit for exercise therapies in women with early breast cancer with AIMSS. This review only yielded seven eligible studies with 400 participants, which is likely to have underpowered the findings. The meta-analysis was challenging due to the considerable heterogeneity amongst the trials, with a wide range of exercise regimens and follow-up periods. Despite these inconclusive findings, exercise needs to be part of routine care for women with breast cancer due to its wide-ranging benefits. Future research in this area would be enhanced with further understanding of the mechanism of AIMSS, a single clear definition of the condition, and phase III randomised controlled trials that are adequately powered to test targeted exercise interventions on the key clinical outcomes in this condition.

Outcomes in Clinically Relevant Patient Subgroups From the EMBRACA Study: Talazoparib vs Physician's Choice Standard-of-Care Chemotherapy.

BACKGROUND: Talazoparib is a poly(adenosine diphosphate-ribose) polymerase inhibitor that causes death in cells with breast cancer susceptibility gene 1 or 2 (BRCA1/2) mutations. METHODS: EMBRACA (NCT01945775) was a randomized phase III study comparing efficacy, safety, and patient-reported outcomes (PROs) of talazoparib (1 mg) with physician's choice of chemotherapy (PCT: capecitabine, eribulin, gemcitabine, vinorelbine) in locally advanced or metastatic breast cancer with a germline BRCA1/2 (gBRCA1/2) mutation. Prespecified patient subgroups were analyzed for progression-free survival, objective response, clinical benefit, duration of response, and safety. PROs were evaluated in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) or triple-negative breast cancer (TNBC) subgroups. RESULTS: Of 431 patients, 287 were randomly assigned to talazoparib and 144 to PCT. Prespecified subgroup analyses showed prolonged progression-free survival with talazoparib (HR+/HER2-: hazard ratio = 0.47, 95% confidence interval = 0.32 to 0.71; TNBC: hazard ratio = 0.60, 95% confidence interval = 0.41 to 0.87) and greater objective response rate (odds ratio = 1.97 to 11.89), clinical benefit rate (odds ratio = 2.05 to 7.77), and duration of response with talazoparib in all subgroups. PROs in HR+/HER2- and TNBC subgroups showed consistent overall improvement and delay in time to definitive clinically meaningful deterioration with talazoparib vs PCT. Across subgroups, common adverse events included anemia, fatigue, and nausea with talazoparib and neutropenia, fatigue, and nausea with PCT. Seven patients (2.4%) receiving talazoparib had grade II alopecia and 22.7% had grade I alopecia. CONCLUSIONS: Across all patient subgroups with gBRCA-mutated advanced breast cancer, talazoparib demonstrated clinically significant superiority in outcomes compared with PCT.